基于SEM模型的流动人口迁移意愿研究

流动人口迁移意愿一直是流动人口研究的热点问题。首次将结构方程模型应用到流动人口迁移意愿影响因素的研究中,通过选取经济条件、生活环境、社会福利保障、迁移意愿4个潜在变量,采用问卷调查获取数据,构建流动人口迁移意愿SEM模型。结果表明:基于SEM的流动人口迁移意愿影响因素分析模型拟合效果较好,为流动人口服务管理相关政策的制定,提供了更加科学的依据。     

Distribution of busy period in stochastic fluid models

We consider the busy period in a stochastic fluid flow model with infinite buffer where the input and output rates are controlled by a finite homogeneous Markov process. We derive an explicit expression for the distribution of the busy period and we obtain an algorithm to compute it which exhibits nice numerical properties.

     

旅游城镇化驱动乡村振兴的影响效应研究

旅游城镇化作为新型城镇化的一种典型模式,是新发展阶段实现乡村振兴的有效路径。以张家界武陵源区为例,紧扣旅游城镇化驱动乡村振兴的关键影响因素和传导路径,基于系统动力学方法对旅游城镇化驱动乡村振兴的影响效应进行仿真模拟。研究发现,旅游城镇化对乡村振兴的驱动是一个复杂的动态过程,需精准分析旅游城镇化作用乡村振兴的不同路径及其影响效应;武陵源区目前的自然发展模式虽能创造较好的经济增长效应,但会造成结构性失业、资源破坏和环境污染等问题;在5种仿真模式中,兼顾经济-社会-环境的协同发展路径是推进乡村振兴的最佳模式;旅游政策影响因子在不同仿真模式中均成为重要的政策因子,印证了武陵源区旅游发展在乡村振兴战略中的重要地位。实现旅游城镇化对乡村振兴的最佳驱动必须从经济增长、社会文化与生态优化三个层面联合发力,以系统化的协同发展路径促进乡村振兴。研究有助于进一步理解旅游城镇化与乡村振兴的多元内在关系,为我国乡村地区尤其是西部民族地区的乡村振兴提供借鉴。     

医药企业负面网络舆情演化及应对策略研究

探讨因媒体不当报道引发医药企业网络舆情危机的演变规律,为企业找寻适宜的对策,有助于提高医药企业危机应对能力。文章以“深圳康泰公司乙肝疫苗信任危机”为例,构建了医药企业负面网络舆情演化和响应策略的系统动力学模型,并采用Vensim PLE软件进行仿真。结果表明:医药企业负面网络舆情经过酝酿、爆发、衰退三个阶段,且呈现爆发时间短、热度高、负面情绪强的特点;医药企业应根据舆情演化阶段特征采取不同应对策略,三个阶段对应有效应急策略依次是提升舆情监测能力、端正担责态度、提高信息公开度和沟通能力、注意形象修复和注重人文关怀。其中,提高信息公开度和沟通能力对负面网络舆情热度的峰值均有明显的削弱效果,整体提升企业舆情应对能力是改善舆情、挽救医药行业信任危机的有力措施。     

Symbolic correlation integral

This paper aims to introduce the concept of symbolic correlation integral SC that is extensively used in many scientific fields. The new correlation integral SC avoids the noisy parameter 𝜀 of the classical correlation integral, defined by Grassberger and Procaccia (1983 Grassberger, P., Procaccia, I. (1983). Measuring the strangeness of strange attractors. Physica D: Nonlinear Phenomena 9(1–2):189–208.[Crossref], [Web of Science ®] , [Google Scholar]) and extensively used for constructing correlation-integral-based statistics, as in the BDS test. Once the free parameter 𝜀 disappears, it is possible to construct a nonparametric powerful test for independence that can also be used as a diagnostic tool for model selection. The symbolic correlation integral is also extended to deal with multivariate models, and a test for causality is proposed as an example of the theoretical power of the new concept. With extensive Monte Carlo simulations, the paper shows the good size and power performance of symbolic correlation-integral-based tests.     

Learning,signaling, and convincing: The role of experimentation in the business modeling process

This study examines experimentation in the business modeling process, unpacking three different roles of experimentation: learning, signaling, and convincing. Learning is an inherent role of experimentation, as managers typically experiment to engage with the environment and to obtain knowledge. This study uncovers another set of roles, which have a symbolic nature. These roles show that experimentation is not just a learning process, but also a strategic legitimation process, aimed at enacting the environment. Experimentation serves the purpose of signaling to potential customers and other stakeholders, and of convincing them to embrace the business model. Furthermore, this study shows that experimentation takes two forms—purposeful interactions and experimental projects—and that these forms can support the different roles of experimentation.     

The potential of online social networking data for augmenting the study of high-risk personal networks among young men who have sex with men at-risk for HIV

Capturing dynamics in high-risk personal networks is essential for preventing HIV transmission. Online social networking data offer incentive to augment traditional selfreported approaches for network enumeration. To explore what online networks reveal about dynamics among high-risk associates, we examine the relationship between egocentric confidant and sex networks and personal Facebook friendship networks of a cohort of young Black men who have sex with men. Although overlap exists between self-reported and Facebook associates, the stabilities of each were unrelated. Confidants who were also Facebook friends with a respondent were, however, more likely to be retained. Thus, Facebook networks contain stable confidants.     

电信运营商投资效益仿真研究——基于系统动力学视角

针对目前电信运营商投资效益分析方法单一的现状，依据电信运营商投资效益非线性、动态性等特征，运用系统动力学方法构建了电信运营商投资效益仿真模型，对电信运营商投资效益影响因素进行了仿真分析。结果表明网络设备延迟投入、综合造价等对投资效益影响较大，在此基础上，给出了电信运营商在针对投入产出水平和提升效益方面的建议。     

Internal Migration and Urban Change in Poland

The paper investigates population change and migration over the period 1984–1994 for communes. There are important conclusions emerging from this study. The first is that we are watching now a profound change of population redistribution patterns in Poland. We observed that direct upwards hierarchical mobility has been markedly modified. The first modification is the substantial reduction of migration from rural to urban locations. There were important changes in the role of cities and towns. Largest cities, massive gainers of the seventies and eighties, have tended to lose population in the mid-nineties. It is likely that they lose population mainly to the neighbouring communes. We believe that a suburbanization process has been put into motion. Medium to large sized towns and cities, in the range between 50,000 and 500,000 as well as small, but not the smallest, towns attract substantial parts of the migration pool.